Frequencies for first 10,000 rows of impacts variable in vehicle dataset :

    VEHICLE |
       ROLE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        571        5.71        5.71
          1 |      6,301       63.01       68.72
          2 |      2,404       24.04       92.76
          3 |        684        6.84       99.60
          9 |         40        0.40      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016